1. Field of the Invention
The present invention relates generally to rotation apparatus for teaching principles of science, and for use as displays for commercial and non-commercial purposes. In particular, the present invention is directed toward displays that produce reverse-rotation motion or variable speed of rotating parts, or both.
2. Description of Related Art
A known, reverse-rotation motion display uses rare earth magnets, such as neodymium and samarium cobalt, to generate reverse-rotation motion. Nevertheless, such rare earth magnets are more expensive than magnets that are not rare earth magnets, which increases the cost of manufacturing the display.
Another known display uses a motor that alternates the direction of rotation at regular intervals to alternate the direction in which the display rotates. Nevertheless, a motor that alternates the direction of rotation is more expensive than a motor that rotates in a single direction, which increases the cost of manufacturing the display.